Prevention of intrusion (free software)

When I am surfing the net there are many times where an intruder comes up and not the site I clicked on. If I repeat clicking on the same spot, eventually the site that was supposed to show up actually does. Is there any software (for Firefox at least) to prevent the intrusion?

can you be more specific? is it happening on ALL links you click on regardless of site or on a particular site only?

I am on Windows 7 - prevously on Windows XP. The browser is Firefox, but it also occurs using Chrome. It doesn't seem to depend on any of these.

It is site specific - it appears that some sites have a means of blocking intruders, while others do not. To clarify - when surfing I will have a web page open with a list of links. For some web pages intruders will appear often when I click on the links. For other web pages there won't be any intrusions.

'Intruders will appear'? Like little gnomes? I am very sorry, but I still don't know what you're talking about.

When I click on the link I expect to get a specific web site defined by the link. Instead a different web site (intruder) appears instead. Repeated clicking the same link often results in other intruders, until, after a few tries, the web site that was supposed to appear shows up.

just to make sure we understand correctly, i'm going to rephrase your situation.
you go to some site and then say click on a link to google. Then instead of taking you to google, the site forwards you to another site that is NOT google. you click the back button and then try again and again until you eventually get google.

It's a pretty easy trick to make it look like you're going to one web site but redirect you to someplace else. There are several ways to do it but it's hard to say which type is giving you trouble. An example would be good. Could you right-click on a sample link, select Copy Link Location, and post the URL along with what it said it was sending you to?

It doesn't even have to be a problem with your computer, per se. Do you have more than one computer on the same network? If so, do the other computers have the same problem? (This would of course not exclude the possibility of a virus of some sort, but would make it more likely someone's been messing with your router 'n stuff.)

Interesting. I ran into a similar problem this morning. I was searching the Oracle web site which has a modified Google search specific to their site. When I manually changed the address to www.google.com, it kept returning to the Oracle search page. I had to open Google in a different tab to get it to load correctly. Probably a cookie that was specific to the tab.

just to make sure we understand correctly, i'm going to rephrase your situation.
you go to some site and then say click on a link to google. Then instead of taking you to google, the site forwards you to another site that is NOT google. you click the back button and then try again and again until you eventually get google.

Is this essentially whats happening?

Yes.

To answer other questions - it is site specific, i.e. site A has a list of links and it may happen on any of the links, while site B has a different list and it never happens. It doesn't appear there are any viruses involved. The phenomenom has nothing to do with the computer or the browser, only the particular source web site.

To answer other questions - it is site specific, i.e. site A has a list of links and it may happen on any of the links, while site B has a different list and it never happens. It doesn't appear there are any viruses involved. The phenomenom has nothing to do with the computer or the browser, only the particular source web site.

I'm strongly leaning towards this being a "feature" of the site itself and not anything on your computer. There are many sites that try to generate ad revenue for themselves by redirecting you to their sponsors instead of going to the link you actually want to. There's really not much you can do to get around this problem other than looking at the link address and manually typing that into your address bar to avoid clicking on the link itself. I cannot conclusively say that this is the case without looking at the site itself but given the fact that its happening with only this one site and not all the others, I'd be shocked if it was something else.
This is unfortunately the reality with using some sites, they may be dishonest and if you need to use the services they provide, then you have to put up with the inconvenience of having to go back and forth or just manually typing in the link address.

To answer other questions - it is site specific, i.e. site A has a list of links and it may happen on any of the links, while site B has a different list and it never happens. It doesn't appear there are any viruses involved. The phenomenom has nothing to do with the computer or the browser, only the particular source web site.